One useful resource is Introduction to Franchising, an online seminar presented in three modules cosponsored by FranNet and the Small Business Administration.
Another handy tool is the AAFD Road Map to Selecting a Franchise from the American Association of Franchisees & Dealers.
Video tutorials and other free resources are available at the Franchisee University offered by the Internicola law firm.
Take a look at the Research Reports from the International Franchise Association.
And consider the difference: Franchising or Licensing: The Best Business Model for Brand Growth.
If the franchise is registered in California, you can use the free Securities & Franchise Search offered by the California Department of Business Oversight.